A new study has revealed that despite their best efforts at hiding it, men are actually more sensitive to a whole range of emotional stimuli than women.

The Royal Mail commissioned Mindlab to test 15 fathers and 15 mothers by hooking them up to electrodes, and found that the males of the species showed stronger reactions to emotive material – particularly when it was classified as “heart-warming”.

Yet getting your own father to exhibit such emotion explicitly is still a challenge, the study showed.

So while they had the men plugged in to the system reading their physiological responses, scientists also read out a series of typical messages that you might find in any slightly unoriginal Father’s Day card this year.

Perhaps surprisingly, the number one phrase that elicited the strongest response was simply being told that they are the “Number one dad”.

“I love you” came only third in the list, beaten by another ego-booster: “You’re my favourite person in the whole world.”

In fourth came “You’re the best”, while making up the last of the top five – a classic – was “Thanks for everything you’ve done for me”.

But if you want to find your own path to plucking your father’s heartstrings, the Royal Mail recommended avoiding altogether anything that sounds a bit overly “saccharine”.

Among the dud phrases that were tested and failed to make the top five were: “You make growing up fun”; “You mean the world to me” and “Everyone deserves someone as special as you”.

And finally, just in case anyone needed proof that dad humour really is the lowest form of comedy, the results also showed little reaction to the card message: “I promise not to put you in a nursing home.” Just goes to show heart-warming beats funny every time.